How do I create a PHP script that will redirect to a custom URL when link added in the URL. For instance, when a user visits this:
http://mydomain.com/link.php?=http://www.google.com
It should redirect them instantly to google.
Ideally, is it possible to ensure that the click itself came locally?
I am aware that this is most likely a very basic PHP code but note that my knowledge of it is very limited which is restricting me from writing it.
You can use the HTTP_REFERER of $_SERVER variable to check whether it is from the local domain.
Reference: http://php.net/manual/en/reserved.variables.server.php
For redirection, try using the below
http://mydomain.com/link.php?r=http://www.google.com
header("Location:".$_GET['r']);
Reference: https://www.php.net/manual/en/function.header.php
I hope the following works for you, you can hard code the $domain variable as mydomain.com
$url = "http://www.php.net/index.html";
$domain = str_ireplace('www.', '', parse_url($url, PHP_URL_HOST));
$refDomain = str_ireplace('www.', '', parse_url($_SERVER["HTTP_REFERER"], PHP_URL_HOST));
if(strcmp($domain, $refDomain) == 0)
{
//your code goes here
header("Location:".$_GET['r']);
}
http://mydomain.com/link.php?url=http://www.google.com
<?php
header("Location: {$_GET['url']}");
?>
This?
Ok, I would like to add a complete answer here.
You could use header to send a redirect header like MrSil said,
header("Location: $url"); // will redirect to $url!
If you want to prevent other people from using your redirect script, you can do something like:
$ref = $_SERVER['HTTP_REFERER'];
$host = parse_url($ref, PHP_URL_HOST);
if($host !== "mydomain.com"){
// out side request
}
But then, HTTP_REFERER can be easily spoofed. So, what would be a better check?
CSRF Protection. It might look like overkill, and it is also not the perfect way to do this stuff, but it helps.
Also, I don't think a perfect solution exists.
Read this for further info about CSRF.